The agency, created after the crisis, analyzed up to 90% of banks' credit cards in the US marketplace and identified more than $20 billion in savings for Americans in light of new regulations.

Implemented in 2009, the Credit Card Accountability Responsibility and Disclosure Act (CARD Act) aimed to curb banking fees and excessive rates charged. The CFPB took over responsibility for the biennial report in 2011, and it tracked credit-card data from that time forward.

The new regulations saved consumers $9 billion in overlimit fees, $7 billion in late fees, and $4 billion in other fees, such as add-on fees, balance-transfer fees, cash-advance fees, and foreign-transaction fees, according to the report. The total savings added up to $20 billion from 2011 to 2014.

"The pre-2009 credit card market was one in which huge numbers of consumers were at needless risk due in large part to inconsistent billing practices, pricing changes, and the proliferation of back-end fees, among other issues," CFPB director Richard Cordray said in a statement.

Here's how consumers are doing better on card fees in the wake of the financial crisis:

Overlimit fees are down, saving consumers $9 billion.

"Had overlimit fees been assessed on overlimit incidents at their 2008 rate, and had average overlimit fees stayed at their 2008 level, consumers would have paid $9 billion more in overlimit fees over the four year period spanning 2011 to 2014," the CFPB report, which analyzed 85%-90% of credit cards, said.

"Overlimit fees, therefore, are all but extinct among issuers," the report adds, noting that the total savings to consumers factoring in the remaining credit cards it could not analyze likely takes the total tally beyond the $9 billion mark.

Postcrisis regulations also reduced how much consumers pay in late fees.

Late fees are down in size as well.CFPB

"Prior to the CARD Act, the average late fee increased dramatically from the mid-1990s, reaching well over $30 by 2005," the report states. "Before the CARD Act, late fees were approaching $35 on average. Shortly after the Act became effective, they reached a low point of just over $23."

Since then, that figure has risen, to about $27 for late payments, the report notes. "Had late fees remained at pre-CARD Act levels, consumers whose accounts are within the CCDB would have paid $7 billion more in late fees between 2011 and 2014."

Other fees are down substantially.

Other fees are down about $4 billion from 2011 to 2014.CFPB

"Other fees," including "add-on fees, balance transfer fees, cash advance fees, and foreign transaction fees," are also down according to the CFPB. "This decline has been driven in large part by a decline in the incidence of add-on fees for debt suspension or cancellation, though the average such fee has not changed much in amount," the report notes.

"Enforcement actions have resulted in issuers refunding nearly $2 billion to consumers since the establishment of the Bureau," it continues. "Had the incidence of such fees persisted at their average level during 2008 to 2011, consumers would have paid close to $4 billion more in such fees since the beginning of 2012."